Mechanical properties of fly ash micro-spheres reinforced aluminum matrix composites were examined by mechanical testing

and tensile fracture morphology was observed by SEM（scanning electron microscope）.The results indicate that tensile strength of the composites is superior to that of pure aluminum matrix.With increasing in fly ash micro-spheres addition

tensile strength is increased with decreasing in plasticity.Meanwhile

fracture morphology of the composites is converted from dimple rupture to cleavage fracture

exhibiting the transformation of plastic to brittle fracture.